Sender Policy Framework (SPF) is an email authentication standard developed by AOL that compares the email sender’s actual IP address to a list of IP addresses authorized to send mail from that domain. The IP list is published in the domain’s DNS record.


DomainKeys Identified Mail (DKIM) which was designed to help ISPs prevent malicious email senders by validating email from specific domains.

Phishers and Spoofers can be sending an email to unaware recipients by pretending to be a trusted sender. By verifying DKIM records the ownership of the domain is confirmed.


SMTP is an acronym for Simple Mail Transfer Protocol. SMTP is a process and set of guidelines that almost every email needs to go through in order to leave one outbox and arrive at another person’s inbox.


SMTP stands for Simple Mail Transfer Protocol. SMTP allows software to transfer email over the internet. The term API stands for Application Programming Interface, which allows software to talk to each other. Therefore the SMTP API allows two or more software platforms to talk to each other over the internet, based on a set of defined parameters and rules between systems.

Dedicated IP

A dedicated IP is a unique internet address dedicated to a particular hosting account.

A dedicated IP is an IP which is used only by a single user or account to send emails. Only that user’s email is sent from that IP, so the volume of email sent from that IP and the reputation of the IP is determined only by the email sent by that user.

Time to Inbox

Time to inbox is the time duration from when an email sent from a user till the emails reaches the receiver’s inbox and is available to read.

Sent Emails

An email that is “sent” means we are attempting to deliver it and waiting for an update from the destination server. An update can take a couple seconds to a few hours.

Delivered Emails

If an email has the “delivered” status it means that it was successfully sent and accepted by the recipient server.

Opened Emails

Opened status means that the email is opened at the recipient’s end. The Open Rate is the percentage of unique ‘opens’ based on the total number of emails delivered.

Clicked Emails

An email gets “Clicked” status when delivered emails have at least one click (excluding the unsubscribe click).

Unsubscribed Emails

Unsubscribed emails indicate those emails to which people have opted out using the unsubscribe link.

Dropped Emails

If your emails are getting dropped by our system it means that the recipient’s email address is listed on one of the suppression lists.

Transactional Emails

One-to-one emails that contain information that completes a transaction or process the recipient has started with you. A common example is in e-commerce, after purchasing an item you receive a email receipt that has information about the item, price, and shipment. Transactional email is sent to individuals rather than a large list of recipients.

Worthy sources of transactional email:

  • Email address confirmations
  • Password resets
  • Purchase receipts
  • “Thank you for [some action]”
  • Account balance updates
  • Auto-responders
  • support requests
  • Cart abandonment
  • Monthly invoices
  • App error alerts (developer tested!)
  • And much more! There’s not really a boundary as to what kinds of actions can trigger an email.

Triggered Emails

Triggered emails are automated emails which get triggered based on specific events, such as an action taken by a website visitor, or any modification in user behavior.


Webhook helps in keeping subscriber’s activity data in sync with your system. Instead of having to poll our API constantly to check for updates, webhooks let you know the instant an event occurs or a response is received from the recipient. This might be someone unsubscribing, opening/clicking on email, bounce and even more. In short, Webhooks allow you to collect information about events as they happen in real-time. Provide a Call Back URL to receive data about events happening on your email campaigns, and we’ll send it to you as the events take place.

SMTP Relay

SMTP relay service is used every time you send an email to someone outside of your address domain. The task of sending your message to outside address is done by SMTP. The job of relay service is to move the message from sender email server to the recipient email server.

A relay is not used where the message is being passed on the same server.

In case of large email volumes, the SMTP relay becomes very important, especially when it comes to marketing emails. Because it’s important that the recipient server trusts that your server is sending good email. An email SMTP relay helps in building the trust by following the best practices leading to better deliverability of your emails.

Opt-in Email

Opt-in email refers to bulk email, such as a marketing or newsletter that is sent out to a mailing list where every member of that list has actively given you permission to send them email. Without obtaining this permission, your email is likely unwanted or unsolicited, and is liable to be marked as spam by the recipient or be “bulked” by the receiving mailbox provider (i.e. delivered directly to the spam folder).